Detail

The ColorSelection is a widget that is used to select a color. It
consists of a color wheel and number of sliders and entry boxes for color
parameters such as hue, saturation, value, red, green, blue, and opacity. It
is found on the standard color selection dialog box ColorSelectionDialog.

Sets the 'previous' color to be color. This function should be called
with some hesitations, as it might seem confusing to have that color change.
Calling colorSelectionSetCurrentColor will also set this color the first
time it is called.